| 报告题目 | Collective Spin-Hall Effect for Electron-Hole Gratings |
| 报告人 | Prof. G. Vignale |
| 报告人单位 | University of Missouri-Columbia, USA |
| 报告时间 | 2013-07-18 |
| 报告地点 | 合肥微尺度物质科学国家实验室九楼会议室 |
| 主办单位 | 合肥微尺度物质科学国家实验室 |
| 报告介绍 | Abstract:
The spin Hall eect, i.e., the generation of a transverse spin current from a charge current and viceversa, has attracted much attention in the past decade: it has now become one of the standard tools for the generation and detection of spin currents in magneto-electronic devices. In this talk I address the ques- tion of how the eect manifests itself in the dynamics of collective states, e.g. an electron-hole density wave induced by optical excitation on the surface of n-doped GaAs. It has recently been predictedy that an electric eld parallel to the wavefronts of an electron-hole grating in a GaAs quantum well generates, via the electronic spin Hall eect, a spin grating of the same wave vector and with an amplitude that can exceed 1% of the amplitude of the initial density grating { an observable eect. I refer to this phenomenon as \collective spin Hall eect". A detailed study of the coupled-spin charge dynamics for quantum wells grown in dierent directions reveals rich features in the time evolution of the induced spin density, including the possibility of generating a helical spin grating from a density grating. |
